Re: [exim] non-address header syntax checking

On Sun, 2006-09-03 at 22:55 +0200, Philippe wrote:
> Since a few weeks, I receive some warnings which look like this :
>
> Message 1GJpyf-0002qL-4W has been frozen (delivery error message).
> The sender is <>.
> The following address(es) have yet to be delivered:
> %mailboxforspam%@%domain%.com <%user%@???>: LMTP error after
> end of data: 554 5.6.0 Message contains invalid header
>
> Do I have to use your system to filter 8-bits headers ?
> Isn't it a little bit too strict ? (I mean, have you ever had false
> positives with that rule)

I've never seen any false positives in my environment, ie., I've had no
complaints about legitimate traffic being rejected due to 8-bit
characters in header field names. however, raw 8-bit characters are
abundant in the values of Subject and From, and Cyrus will rewrite those
to X's (its default behaviour).

we have seen false positives from stray NUL bytes, so we run messages
through tr(1) in the transport if Exim has found any NULs.
--
Kjetil T.